Roof structure



June 17, 1941. I H. KRUEG ER 4 ,6

. 4 ROOF STRUCTURE 'FildDec. 19, 1940 INVENTOR Patented June 17, 1941 ROOF STRUCTURE Richard H. Krueger, Detroit, Mich, assignor to H. E. Beyster Corporation, Detroit, Mich., a corporation of Michigan Application December 19, 1940, Serial No. 370,744

' to the accompanying drawing, and then claimed,

19 Claims.

This invention relates to roof structures and is particularly adaptable to that type of roof structure required to extend over and cover a relatively long span, the principal object being the provision of a structure of this type that is simple in construction, light in weight and economical to build.

Other objects of the invention include the provision of a roof structure capable of use over relatively long spans but which will be materially lighter in weight than conventional roof structures of an equivalent span and yet will be amply strong for the purpose required; the provision of a roof structure of the type described in which the principal elements consist of angularly sectioned sheet metal members extending longitudinally of the span; the provision of a roof structure of the type described in whichthe roof has a continuous thickness determined by the depth of the angularly sectioned sheet metal members extending longitudinally of the span; the provision of a roof structure of the type de scribed in which both the outer and inner surfaces of adjacent angularly sectioned longitudinally extending members are rigidly tied together by metal members; the provision of a roof structure of the type described in which the outer faces of the longitudinally extending members are tied together by diagonally extending plates or strips preferably spaced from one another; the provision of a roof structure of the type described in which the various longitudinally extending angularly sectioned members are secured to each other and to a metallic inner covering in such a manner as to form the corner portion thereof into rigid and substantially unyielding sections serving to brace the edge portions of the roof structure between columns against bulging under excessive load; the provision of a construction as above described in which one face of the longitudinally extending members is completely closed by plates of metal co-acting with the longitudinally extending members to form box sections; the provision of a roof structure of the type described affording high insulation characteristics against loss of heat; and the provision ofa roof structure as above described provided with means for reinforcing the longitudinally extending angularly sectioned metal members against deformation under load.

The above being among the objects of the present invention, the same consists in certain novel features of construction and. combinations of parts to be hereinaiter described with reference having the above and other objects in .y ew.

In the accompanying drawing which illustrates suitable embodiments of the present invention and in which like numerals refer to like parts throughout the several different views Fig. l is a fragmentary perspective view of a building provided with a roof constructed in accordance with the present invention;

Fig. 2 is an enlarged plan view of one of the sections of the roof shown on the building in Fig. l, with a portion of the covering and filling material removed to better illustrate the construction;

Fig. 3 is an enlarged fragmentary, partially brokempartially sectioned perspective view of a portion of the roof structure shown in Figs. 1 and 2;

Fig. 4 is a still further enlarged fragmentary vertical sectional view taken on the line 44 of Fig. 2 and illustrating a preferred method of securing the longitudinally extending sheet metal members to a roof beam where the latter is employed;

Fig. 5 is a View similar to Fig. 3 but illustrating a modified form of construction; and,

Fig. 6 is a view similar to Fig. 3 but showing a still further modified form of construction.

' Roof structures required to span a relatively reat distance without support have, in accordance with conventional practice, involved a considerable amount of structural steel necessarily involving great Weight and running into considerable cost in their construction. In addition, in conventional constructions when the space below the roof requiresheating, it requires the application of insulating material to the roof which has no'material value from the standpoint of increasing the strength thereof but serves primarily, from a structural standpoint, as an additional deadload which must be carried by the roof structure.- It is the main purpose of the present invention to provide a roof structure in which the use of structural steel members is minimized to a great extent and may even be eliminated entirely, the'structural'steel members of conventional constructions being replaced by sheet metal members of angular cross-sectional configuration, together with inner and outer boundary members fixed thereto, the whole being so constructed and arranged'as to providea roof with ample factor of safety and yet weighing only a fraction of a corresponding roof constructed in accordance with conventional practice. Additionally, with the structure of the present invention heat insulating material may be compressive stress, thus enabling the same depth and weight of structure to be employed for curved or arched roofs having greater spans than in the case of flat roofs. This latter type of construction is illustrated in the drawing by way of illustration and not by way of limitation as will be readily appreciated, although the application of the invention to the convexly curved or arched type of roof does include certain structural advantages as 'compared to a flat roof and which, accordingly, constitutes a more limited phase of the present invention.

Referring to Fig. 1, a fragment of a building is there illustrated as comprising a plurality of adjacent sections or bays indicated generally at I0, each section or bay having its own convexly curved or arched roof indicated generally at I2. It will, of course, be understood that the equivalent of one section or bay it of one roof may, when provided with side and end Walls, constitute an individual building all by itself, the multiple type being shown merely by way of illustration. In the particular building structure shown the type of structure includesa side wall indicated generally at M, an open front which may or may not be closed by suitable walls, doors or the like, and being open on the side opposite the sides l4 into the next section or bay.

It may be assumed for the purpose of description that sections or bays Ill are of relatively great width, for instance in the neighborhood of 100 feet, and that no supporting columns are permitted between the side walls in the main portion of the same. Accordingly, along each side of each section or bay l9 columns l6 are provided. These columns are connected at the top by structural steel members such as channels it rigidly secured thereto. Although not necessary in the broader aspects of the present invention, it willsometirnes be desirable that correspondingcolumns It on opposite sides of each section It be connected together by a structural steel member such as an I-beam 2B curved in conformance with the curvature of the roof.

Accordingly, between each pair of adjacent structural members a roof constructed in accordance with the present invention is provided.

In the preferred form of the structure illustrated in Figs. 2, 3 and 4 it will be noted that the roof 'is made up of a plurality of main longitudinally extending members indicated generally at 22 longitudinally curved into conformance with the desired curvature of the roof and arranged parallel with the corresponding structural members 20 at each side of the section. In referring to the members '22 as extending longitudinally it will, of course, be appreciated that by flongitudinally is here meant longitudinally of the corresponding "sections between column T5, for instance as illustra'ted in Fig. 2 and, accordingly, they extend transversely of the roof structure as a whole in the construction illustrated in Fig. '1.

Each of the members 22 is formed from sheet imet'al, .the'gaug'e depending upon the span of the roof and the weight to be supported thereby, and

includes at least one inverted channel-shaped part having side walls 24 integrally connected together by a top wall 26. One or more of such channel-shaped elements may be included in a single longitudinally extending member 22, relatively deep sections, for instance between 18 and 24 inches in depth preferably including only one channel portion to each member, while shallower sections may have two or more channel portions to each member. In the particular construction it may be assumed that these channel portions are approximately one foot in depth in which case it is feasible to form each member to provide two of such channel members in which case two adjacent channel members have the marginal edge of their adjacent side walls 24 integrally connected together by a wall 28 parallel to the connecting walls 26 and of substantially the same width. The remaining margins of the channelshaped portions are each provided with outwardly directed integral flanges 30 parallel to the walls 26 and 28 and of half the width of the wall 28.

Although these longitudinally extending memhere 22 may be arranged with the flanges '30 overlapping and fixed together by welding, riveting or the like, preferably they are arranged with the free edges of the flangestil in a common plane and abutting one another as illustrated in Fig. 3. They are secured together by means of longitudinally extending strips or plates 32 of sheet steel of suitable thickness which underlie the various Walls 28 and flanges 3'0 andare suitably secured thereto as by riveting, welding, or any other suitable means. The plates or strips 32 are preferably of the same width as the longitudinally extending member's 22 but in order to facilitate assembly of thestructure and to render it more rigid generally, preferably Onnl'afgin' breach plate 32 is centrally aligned with the center of the wall 28 of each section so that the abutting or substantially abutting joint between each 'of the longitudinally extending members 22 is located centrally of each plate or strip 32'.

' Each longitudinally extending member 22 and a corresponding plate 32 is preferably assembled together before being applied to the roof structure so that'wnen applied "to the roof all that remains 'to'uo is to weld or otherwise secure the overlapping art of the adjacent "longitudinally eiteh'dihg' section 22 of each assembly to the projecting edge of the cooperating plate 32 of the next adjacent assembly. Additionally, in the manufacture or the longitudinally extending members '2': it is preferable that each is welded "or otherwise fixed to a 'corre'sporrdingplate 32 in substantially fiat or "straight form and then the resulting assembly subjected to a suitable "operation between rolls or the like to bring it to'the curvature desired inth-e roof "structure.

It may be noted at this'point that seldom, if ever, will the entire leng'thof the members 22, or the plates 32 for that matter, beiormed from a single strip ofmetal for manufacturing reasons. They may be formed in suitable lengths "as, for

instanca. twenty-five feet, and such lengths "s'e'ction"22 with its corresponding plate 32 is preferably positioned with one side margin thereof resting upon the upper surface of one of the curved structural members 20, as illustrated in Fig. l, with the corresponding edge flange 3t overlying the upper flange of the struc-' tural member 26 and suitably welded thereto. In such case it is, of course, necessary to laterally extend the corresponding plate member-32 and terminate it along the edge of such flange 30 as indicated in Fig. 4. The opposite ends of the member 22 and its plate 32 are, of course, suitably fitted to and secured as by Welding or the like to the corresponding structural members 18 at the ends of the roof section. After the first longitudinally extending member 22, together with its corresponding plate 32 is fixed to one of the structural members 20 as described, additional members 22 together with their plates 32 are then positioned in place one against the other and securely welded together and to themembers l8 as previously described until the entire space between the structural members 29 has been filled, and the last longitudinally extending member 22 welded to the remaining structural member 20 as indicated in Fig. 4. The members 32 thus serve to provide a continuous and substantially smooth and fiat or curved under-surface for the roof structure. By continuous is meant that adjacent plates substantially abut one another, and While such plates 32 are preferably imperforate for a reason which will hereinafter be more apparent, i. e. so as to act as a wall of a mould, where extreme lightness is desired holes may be punched in them to aid in attaining this result.

After the above has been accomplished, then the entire upper surface thereof is covered with diagonally extending metallic strips or flat bars 38 suitably secured in place to the wallportions 26 as by welding or the like. These bars til extend at preferably a 45 degree angle with respect section capable 'of withstanding a high degree of compressive stress without deformation. The entire structure is, therefore, built up of a plurality of adjacent box section girder-like members rigidly secured together at both top and bottom from which it will be apparent that an extremely stiff and rigid roof structure is provided. Calculations indicate that With this construction a roof structure equally as strong as those of conven-. tional constructions yet weighing only a fraction of the weight of conventional constructions can be produced. The saving in weight isin and of itselfan indication of the economy in providing a roof structure of this type as compared to conventional types of roof constructions, not only in itself but also in the columns, etc, required to support the roof. This is particularly true in the curved or arched type of roof to which the present construction is particularly adaptable in view of the fact that in such constructions all of the members are constantly subjected to compressive stresses only thus peculiarly adapting this structure to such types of roof construction.

After the roof has been constructed. as thus far described it may, if desired, be covered in the state described. with a suitable weather repellant to'the longitudinally extending members 22 and v are of heavier gauge than the members 22 and the plates 32 and are preferably spaced from areas within lines such as the line 553 in Fig. 2, together at such frequent intervals as to render the corner portions substantially integral. This is illustrated in Fig. 2 by illustrating a greater concentration of Xs, here employed to indicate relative points of welding between the members 22 and the plates 32, than in the remaining areas of the structure. Additionally, it will, of

course, be understoodthat turnbuckle controlled tension members such as $2 may be stretched between the'structural members it on opposite sides of the structure in line with the columns It and at any desired point intermediate the columns '56, as for instance in the center ofeach roof section as illustrated in Fig. 2, to provide the necessary resistance to spreading tendencies of the roof under load.

It will be observed from an inspection-of Figs. 3 and4 in particular that the plates 32 cooperate with "the longitudinally extending members 22 7 to close each channel portion 2 i--2t into 'a box covering or sheathing of any suitable or desirable type.v However, in accordance with a further phase of the present invention it is preferable to fill the space between the channels 2% and 26 with some material 5%! that may have either one or the other or both of two characteristics. One characteristic which such material 59 may have is thecharacter of insulation against transferof heat therethrough in which case the material 50 may be. of any; suitable or conventional heat insulating material capable of being readily applied between and over the channels 2425 and may be either of a loose type of material or some type capable of being formed into a more or less integral mass. On the other hand, the material 50 may be of. a character which will reinforce the members 22, 32 and 33 against buckling, warping or the like and in such case the material 5!] may! be concrete or the like simply poured or cast into place. The material 50 is preferably applied to a depth suificient to imbed the members 38 a material distance therein ,as brought out in Fig. 3. It will be appreciated that where a material such as concrete or other cemehtitious material is employed the entire roof structure assumes the form similar to that ofia reinforced. concrete roof but including metallic members of a new form through which the'principal strengthof the roof is obtained. Concrete, of course, does not have a high degree of resistability'to transfer of heat through it and, accordingly, where concrete is employed some material of ahigher insulating value is preferably provided over the upper surface of the same to enhance the heat insulation qualities thereof when desired.

' 'On the other hand the cement, such as Port- 7 land cement, may be mixed with a suitable material of high heat insulation qualities and be employed for the material in which case the material so not only will reinforce the metallic portion of the structure against warping or distortion under loadbut will also serve as a heat insulation material for insulating the roof against transfer of' heat therethrough. One material which is ideally suitable to mix with cement for this purpose is vermiculite which, when mixed with suitable quantities of Portland cement, may

be cast into place and thereafter not only-en-- hance the strength of the roof itself but, due to the air cells which the vermiculite causes to be distributed throughout the mixture, forms an excellent heat insulation for the roof.

In any event after the material 50 has been applied to the roof structure, its outer surface is then preferably covered by a suitable roofing material such as 52 applied in any suitable or conventional manner for protecting the material 50 against the effects of weather thereon.

It will be appreciated from the foregoing that the structure provided in accordance with the present invention enables a roof of extended span to be constructed with a relatively simple, efiicient and unusually light and, therefore, economical manner, and that it may be easily and. efiiciently insulated against the transfer of heat therethrough.

Although the construction illustrated in Fig. 3 including the inverted channel-shaped portions which cooperate with the plates 32 to provide box-like sections is preferable, particularly where the spans are of great length, the construction illustrated in Fig. 5 will be found satisfactory, particularly where employed with shorter spans and usually will be found to be more economical to use and more easily fabricated. As will be noted from an inspection of Fig. 5 the construction is substantially the same as that illustrated in Fig. 3 except that the members 60, corresponding with the members 22 previously described, are of a different form and instead of embodying separate plate members 32 are constructed so as to provide their own .plate members. In other words, in Fig. 5 each of the members 60 is formed from sheet metal and each includes a channel sectioned end portion. 62 the channel of which opens laterally. The lower flange of each channel end 62 is integrally connected to a downwardly offset parallel plate portion 64, the amount of the ofiset being substantially equal to the thickness of the material from which the members 60 are constructed. The free edge of the upper flange of each channel end 62 is provided with a downwardly extending flange 66 for enhancing the rigidity thereof. In assembling the members 60 together the free marginal edge portion of the plate portion 64 of each member 60 is arranged in underlying relationship with respect to the lower flange of the channel end 62 of the adjacent member, as illustrated, and with the free edge of the plate portion 60 in substantially abutting relationship with respect to the shoulder formed between the lower flange of the channel end portion and the adjacent plate portion 64. The free marginal edge of the plate portion 64 of each member 60 is, of course, welded or otherwise suitably secured to the lower flange of the channel end 62 of the cooperating member 60 so as to rigidly secure the adjacent members -60 together. It will thus be appreciated that the plate portion 64 of each member serves the same purpose as the plate members 32 in the first described construction and the channel end 62 of each member serves the same purpose as the channels 24-26 of the first described construction. The same bars 38 are provided in this construction and in the same manner as in the previously described construction, that is they are diagonally disposed with respect to the length of the roof section and overlie andare suitably secured as by welding or the like to the upper flange of each channel end 62 over which they extend in the same manner as described in connection with the first described construction.

Suitable material 68 which may be the same as the material 50 previously described may fill the entire space between adjacent members 60 and extends upwardly over the diagonals 38 as in the previously described construction and thereby serve the same purpose and effect. The main difference between this construction and the previously described construction is, of course, that it does not provide for the box-sections provided for in the previously described constructions, but on the'other hand is lighter and slightly more economical to build.

It will be appreciated that unless the plates '32 of, the construction illustrated in Fig. 3, and the plate portions 64 of the construction illustrated in Fig. 5, are formed to provide a plurality of holes through them and backed by suitable sound insulating material, or are covered on their lower side with suitable sound insulating material, they will serve to reflect sound waves and tend to make the building noisy. Where, of course, the plates 32 or portions 64 are formed to provide a plurality of holes therethrough and the open space above the plates filled with a suitable sound insulating material the reflection of sound waves will be materially lessened. However, where the sound absorbing qualities of the roof structure are important, the construction illustrated in Figs. 1 to 4, inclusive, may be readily modified to materially lessen its sound reflecting characteristics in the manner illustrated in Fig. 6. The construction illustrated in Fig. 6 is identical to the construction illustrated in Fig. 3 except in one particular and, accordingly, it will only be necessary to discuss this single change in order to fully disclose the construction.

The main difference between the construction illustrated in Fig. 3 and that illustrated in Fig. 6 is that in Fig. 6, instead of using the plates 32 as in Fig. 3, the plates 32 are replaced with bar members 10 which may be identical with the bar members 38 except that they extend in an angularly opposite direction to the bar member 38, perpendicular to the length of the bar members 38 where the bar members 38 are disposed at an angle of 45 to the members 22, and are welded to the lower walls 28 and flanges 30 of the members 22. Preferably the bar members 10 are spaced in approximate accordance with the spacing of the bar members 38 so as to provide a plurality of openings or spaces between the various bar members 10 opening upwardly into each of the downwardly facing channels of the members 22. The space between each downwardly opening channel 2426 above the various bar members 10 is preferably partially or completely filled with a suitable sound insulation material such as 12. This sound insulating material may be of any conventional or suitable type such as the various fibrous materials conventionally used or, if desired, may be of the same type of material as previously described for the material 50 when desired to be of heat insulating characteristics, namely a mixture of cement and vermiculite as this mixture is not only a good heat-insulating medium but also a good sound absorbing med m.

By employing the construction illustrated in Fig. 6 a roof of substantially the same strength for the same amount of material as the construction illustrated in Fig. 3 may be provided, the diagonally extending and oppositely directed bars 38 and 10 which are welded to the upper and lower faces respectively of members 22 serving to impart great rigidity to the structure. It will, of course, be appreciated that modifications in the assembly of the roof structure as-described in connection with the structure shown in Fig. 3 are necessary in assembling the roof structure shown in Fig. 6, it being necessary in the latter case to apply the bar members 19 independently of the roof members 22 instead of simultaneously therewith as is possible with the plates 32 in the construction illustrated in Fig. 3. 1

Formal changes may be made in the specific embodiments of the invention described without departing from the spirit or substance of the broad invention,- the scope of which is commensurate with the appended claims.

What is claimed is:

1. A roof structure for buildings comprising a plurality of sheet metal members of angular section extending between opposite edges of said roof section, sheet metal plate means secured to the underface of said members in substantially unbroken relationship over the entire'area. thereof. and transversely extending metallic bars extending across and fixed to the upper surfaces of said members, said members serving as the major load carrying elements of said structure.

2. A roof section comprising, in combination,

angularly sectioned sheet metal members of a depth substantially equal to the thickness of the roof extending from one edge thereof to an opposite edge thereof and provided with transversely extending surfaces at the upper and lower surfaces thereof arranged in parallelism with the general plane of the roof, metallic plate means rigidly fixed with respect to the lower surfaces of said members and forming a substantially continuous under-surface therefor, and spaced metal members, said members serving as the major load carrying elements of said structure, and means filling the upwardly opening spaces be.- tween said members serving to reinforce said members against distortion.

4. A roof structure for buildings comprising a p urality of sheet metal members of angular section extending between opposite edges of said;

roof section, sheet metal plate means secured to the underface of said members in substantially unbroken relationship over the entire area thereof, transversely extending metallic bars extending across and fixed to the upper surfaces of said members, said members servingas themaior load carrying elements of said structure, and means serving to reduce transfer of heatthrough said roof structure filling the upwardly opening space between said members.

5. A roof sectioncomprising a. brill-hey of sheet. a

metal elements extending from one edge of ,said section to an opposite edge thereof ingeneraliy parallelism to each other, each member comprising an angularly sectioned portion and a transversely directed plate-like portion fixed to the lower portion thereof in offset relation with respect to said angularly sectioned portion, the plate-like'portion of one of said members overother of said members and rigidly fixed thereto so. as to. form a substantially continuous plate-like surface for thelower surface of said section, and transversely directed spaced metalmembers over lying thefu'pper surface of. the first mentioned member and rigidly fixed thereto. v

6. .A roof section comprisinga plurality of sheet metal elements ,extendingfrom one edge of said section to an opposite edgethereof in generally parallelism to each other, eachmernber comprising an angularly sectionediportion and a transversely directed plate-like portion fixed 'to the lower portion thereof in offset relation with respect to said angularly sectionedportion, theplate like portion of one of said members, overlapping the angularly sectioned portion of another of said members and rigidly fixed thereto so as to form a substantially continuous plate-like surface for the lower surface of said section, anda plurality of spaced parallel diagonally arranged metallic bar members extending diagonally across the upper surfaces of the first mentioned members {and rigidly fixed thereto.

7. A curved or arched roof section comprising, in combination, a plurality of longitudinally arched sheet metal members arranged 'in parallel and adjacent relationship and extending between opposite sides'vof said section, each of said members comprising one or more angularlysectioned portions provided with laterally directed top and bottom surfaces, plate means fixed to the lower laterally directed surfaces of said member and cooperating to form a substantially continuous bottom surface for said section, "and alplurality of spaced parallel bar members extending diagonally over the upper laterally directedsurf'aces of said members and rigidly fixed thereto.

{ 8.A- curved or arched roof section comprising, in combination, a plurality of longitudinally arched sheet metal: members arranged in parallel and adjacent relationship andextending between opposite sides of said sectionfeach of said members comprising one or more angularly sectioned portions provided with laterally directed top and bottom surfaces, plate means fixed to the lower laterally directed surfaces of said member andcooperating to form a substantially continu ous bottom surface for said section, a plurality of spaced parallel bar members extending diagonally over the upper laterally directed surfacesof said members and, rigidly fixed thereto, and heatinsulating material filling the space between a'djacent angular sections of said members.

9. A curved'or arched roof section comprising, in combination, a plurality of longitudinally arched sheet metal members arranged'in parallel and adjacent relationship and extending between opposite sides of said section, eachof said members comprising one or more angularly sectioned portions provided with laterally directed top and bottom surfaces, plate means fixed to the lower laterally directed surfaces of said member and cooperating'to form a substantially continucus bottom surface for said section, a plurality of spaced parallel bar members extending diagonally over the upper laterally directed surfaces of said members, and rigidly fixed thereto, and a substantially rigid mass filling the-space between adjacent of said singularly sectioned portions and extending above'and imbedding said bar members therein serving to reinforce said rnenyibersv against distor tion under load. Q

10. A roof section comprising, in combination, a plurality of load sustaining members extending lapping the angularly sectioned portion of an- 5 between opposite sides thereof formed from sheet metal to present downwardly opening channel sections, substantially flat plate means extending between and fixed to the lower faces of said members whereby to cooperate therewith to form said members into box-like sections, and a plurality of spaced parallel metallic bar members overlying the upper surface of said members and extending diagonally with respect to the length thereof and rigidly fixed thereto.

11. A roof section comprising, in combination, a plurality of load sustaining members extending between opposite sides thereof formed from sheet metal to present downwardly opening channel sections, substantially fiat plate means extending between and fixed to the lower faces of said members whereby to cooperate therewith to form said members into box-like sections, said plate means projecting laterally beyond at least one edge .of a channel section of its corresponding member in overlapping relationship with respect to the next adjacent channel section of the next adjacent member and rigidly fixed thereto, and a plurality of spaced parallel metallic bar members overlying the upper surface of said members and extending diagonally with respect to the length thereof and rigidly fixed thereto.

12. A roof section comprising, in combination, a plurality of load sustaining members extending between opposite sides thereof formed from sheet metal to present downwardly opening channel sections, substantially flat plate-meansextending between and fixed to the lower faces of said members whereby to cooperate therewith to form said members into box-like sections, a plurality of spaced parallel metallic bar members overlying the upper surface of said members and extending diagonally with respect to the length thereof and rigidly fixed thereto, and means filling the space between said channel sections serving to retard the transfer of heat therethrough.

13. A roof section comprising, in combination, a plurality of load sustaining members extending between opposite sides thereof formed from sheet metal to present downwardly opening channel sections, substantially flat plate means extending between and fixed to the lower faces of said members whereby to cooperate therewith to form said members into box-like sections, a plurality of spaced parallel metallic bar members overlying the upper surface of said members and extending diagonally with respect to the length thereof and rigidly fixed thereto, and a substantially rigid mass filling the space between said channel sections and serving to reinforce said members against distortion.

14. A roof section comprising, in combination, a plurality of load sustaining members extending between opposite sides thereof formed from sheet metal to present downwardly opening channel sections, substantially fiat plate means extending between and fixed to the lower faces of said members whereby to cooperate therewith to form said members into box-like sections, a plurality of spaced parallel metallic bar members overlying the upper surface of said members and extending diagonally with respect to the length thereof and rigidly fixed thereto, and a substantially rigid mass including a mixture of Portland cement and vermiculite completely filling the space between adjacent channel sections whereby to reinforce said members against distortion and to minimize the transfer of heat therethrough.

15. A roof section comprising, in combination, a plurality of sheet metal members extending between opposite sides thereof, each of said members comprising a laterally opening channel sectioned end portion and a laterally extending plate portion secured to the lower flange of each channel end portion, said members arranged with the free marginal edge of each plate portion in underlying relation with respect to the lower flange of the channel end of the next adjacent member and rigidly fixed thereto, and a plurality of spaced parallel metallic bar members arranged in overlying relationship with respect to the upper flange of the channel end portion of each of said members and extending transversely with respect thereto and rigidly fixed thereto.

16. A roof section comprising, in combination, a plurality of sheet metal members extending between opposite sides thereof, each of said members comprising a laterally opening channel sectioned end portion and a laterally extending plate portion secured to the lower flange of each channel end portion, said members arranged with the free marginal edge of each plate portion in underlying relation with respect to the lower flange of the channel end of the next adjacent member and rigidly fixed thereto, a plurality of spaced parallel metallic bar rrlzmbers arranged in overlying relationship with respect to the upper flange of the channel end portion of each of said members and extending transversely with respect thereto and rigidly fixed thereto, and means filling the space between said channel sections serving to retard the transfer of heat therethrough.

17. A roof section comprising, in combination, a plurality of sheet metal members extending between opposite sides thereof, each of said members comprising a laterally opening channel sectioned end portion and a laterally extending plate portion secured to the lower flange of each channel end portion, said members arranged with the free marginal edge of each plate portion in underlying relation with respect to the lower flange of the channel end of the next adjacent member and rigidly fixed thereto, a plurality of spaced parallel metallic bar members arranged in overlying relationship{ with respect to the upper flange of the channel end portion of each of said members and extending transversely with respect thereto and rigidly fixed thereto, and a substantially rigid mass filling the space between said channel sections and serving to reinforce said members against distortion.

18. A roof section comprising, in combination, a plurality of sheet metal members extending between opposite sides thereof, each of said members comprising a laterally opening channel sectioned end portion and a laterally extending plate portion secured to the lower flange of each channel end portion, said members arranged with the free marginal edge of each plate portion in underlying relation with respect to the lower flange of the channel end of the next adjacent member and rigidly fixed thereto, a plurality of spaced parallel metallic bar members arranged in overlying relationship with respect to the upper flange of the channel end portion of each of said members and extending transversely with respect thereto and rigidly fixed thereto, and a substantially rigid mass including a mixture of Portland cement and vermiculite completely filling the space between adjacent channel sections whereby to reinforce said members against distortion and to minimize the transfer of heat therethrough.

19. A roof structure for a building comprising metal bar members overlying the upper surface 10 of said sheet metal members and arranged in spaced parallel relation with respect to each other, said last mentioned metallic bar members extending diagonally with respect to the length of said sheet metal member but in a direction opposite to the direction of angular extension of the first mentioned bar members and rigidly fixed to said sheet metal members.

RICHARD H. KRUEGER. 

